Hello Keith and everyone,
I have just read the latest JEC bulletin about a replacement battery for a series 2. The battery on my 1976 Daimler Double Six Avon-Stevens Convertible died suddenly several weeks ago (it was less than 3 years old!) and I embarked on the same saga. Last time I just went to my local ATS outlet and they were able to get me the correct 089 battery (the 069 is also suitable). This time I spent ages researching on the Internet, eBay, etc., and failed completely. I did eventually buy an 089, but found it wouldn't fit, so treated my 1964 Alvis TE21 Park Ward saloon to this one (her battery was 8 years old and still going strong) and continued my search.
The most useful thing I did was to take the battery and the box to show all the battery experts what I needed. Eventually, we discovered from various charts that an 072 battery also has sufficient capacity: it is also the correct shape and it is available as UNIPART GBA3072. Battery replacement is clearly going to be problem in the future and I have found a solution without having to modify the battery box. Perhaps it would be useful to publicise this in the bulletin.
David.